Re: Dumb Question - Casting

On Thu, Feb 18, 2010 at 10:50 AM, Ashley Sheridan <ash@ashleysheridan.co.uk> wrote: > On Thu, 2010-02-18 at 09:47 -0600, Chuck wrote: > >> Sorry, been doing heavy perl and haven't written any PHP in 3 years so a tad >> rusty. >> >> Can someone explain why the second expression in this code snippet evaluates >> to 7 and not 8? >> >> $a = (int) (0.1 +0.7); >> >> echo "$a\n"; >> >> $x = (int) ((0.1 + 0.7) * 10); >> >> echo "$x\n"; >> >> $y = (int) (8); >> >> echo "$y\n"; > > > It works as expected if you take out the int() parts in each line. I'm > not sure why, but the use of int() seems to be screwing around with the > results. That's why the first line outputs a 0. > > Thanks, > Ash > http://www.ashleysheridan.co.uk > Another fine example of floating point math. <?php $x = ((0.1 + 0.7) * 10); echo "((0.1 + 0.7) * 10) === $x\n"; // ((0.1 + 0.7) * 10) === 8 var_dump(8 == $x); // bool(false) var_dump($x - (int) $x); // float(1) var_dump(8 - $x); // float(8.8817841970013E-16) ?> Andrew